Where is the Missile Expansion in Training Chamber Access (Metroid Prime Origins)?

The Missile Expansion is in Training Chamber Access, Chozo Ruins. To get there you need Missile Expansion, Morph Ball, Morph Ball Bomb, Varia Suit, Charge Beam, Boost Ball, Space Jump, Wave Beam, Power Bomb Expansion, Super Missile, Spider Ball, Ice Beam, Grapple Beam first (starting a new game).

What you need first

Starting a new game from Landing Site, get these first, in this order, then go to Training Chamber Access (221 rooms in all):

1. Missile Expansion in Landing Site (0 rooms; needed for Morph Ball (Missile))
2. Morph Ball in Ruined Shrine (9 rooms; needed for Missile Expansion (Morph Ball))
3. Morph Ball Bomb in Burn Dome (13 rooms; needed for Varia Suit (Morph Ball Bomb))
4. Varia Suit in Sunchamber (10 rooms; needed for Missile Expansion (Varia Suit))
5. Charge Beam in Watery Hall (7 rooms; needed for Wave Beam (Charge Beam))
6. Boost Ball in Phendrana Canyon (31 rooms; needed for Space Jump (Boost Ball))
7. Space Jump in Alcove (21 rooms; needed for Wave Beam (Space Jump Boots))
8. Wave Beam in Chapel of the Elders (21 rooms; needed for Missile Expansion (Wave Beam))
9. Power Bomb Expansion in Ice Ruins West (6 rooms; needed for Grapple Beam (Power Bomb))
10. Super Missile in Observatory (8 rooms; needed for Grapple Beam (Super Missile))
11. Spider Ball in Quarantine Cave (9 rooms; needed for Grapple Beam (Spider Ball))
12. Ice Beam in Antechamber (39 rooms; needed for Grapple Beam (Ice Beam))
13. Grapple Beam in Storage Depot B (18 rooms; needed for Missile Expansion (Grapple Beam))

Last stretch

From Storage Depot B, door by door:

1. Storage Depot B: go through the door to Ore Processing → Ore Processing (Ice Door; needs Ice Beam)
2. Ore Processing: go through the door to Waste Disposal → Waste Disposal (Ice Door; needs Ice Beam)
3. Waste Disposal: go through the door to Main Quarry → Main Quarry (Ice Door; needs Ice Beam)
4. Main Quarry: go through the door to Quarry Access → Quarry Access (Wave Door; needs Wave Beam)
5. Quarry Access: go through the door to Transport to Tallon Overworld South → Transport to Tallon Overworld South (Wave Door; needs Wave Beam)
6. Transport to Tallon Overworld South: take the elevator → Transport to Phazon Mines East assumed
7. Transport to Phazon Mines East: go through the door to Transport Tunnel E → Transport Tunnel E (Ice Door; needs Ice Beam)
8. Transport Tunnel E: go through the door to Great Tree Hall → Great Tree Hall (Ice Door; needs Ice Beam)
9. Great Tree Hall: go through the door to Transport Tunnel D → Transport Tunnel D (Ice Door; needs Ice Beam)
10. Transport Tunnel D: go through the door to Transport to Chozo Ruins South → Transport to Chozo Ruins South (Ice Door; needs Ice Beam)
11. Transport to Chozo Ruins South: take the elevator → Transport to Tallon Overworld South assumed
12. Transport to Tallon Overworld South: go through the door to Transport Access South → Transport Access South
13. Transport Access South: go through the door to Reflecting Pool → Reflecting Pool (Ice Door; needs Ice Beam)
14. Reflecting Pool: go through the door to Reflecting Pool Access → Reflecting Pool Access
15. Reflecting Pool Access: go through the door to Hall of the Elders → Hall of the Elders
16. Hall of the Elders: go through the door to East Furnace Access → East Furnace Access (Ice Door; needs Ice Beam)
17. East Furnace Access: go through the door to Furnace → Furnace (Ice Door; needs Ice Beam)
18. Furnace: go through the door to West Furnace Access → West Furnace Access
19. West Furnace Access: go through the door to Energy Core → Energy Core
20. Energy Core: go through the door to Energy Core Access → Energy Core Access
21. Energy Core Access: go through the door to East Atrium → East Atrium
22. East Atrium: go through the door to Gathering Hall → Gathering Hall
23. Gathering Hall: go through the door to Gathering Hall Access → Gathering Hall Access
24. Gathering Hall Access: go through the door to Arboretum → Arboretum (Missile Blast Shield; needs Missile)
25. Arboretum: go through the door to Arboretum Access → Arboretum Access (Missile Blast Shield; needs Missile)
26. Arboretum Access: go through the door to Ruined Fountain → Ruined Fountain
27. Ruined Fountain: go through the door to Meditation Fountain → Meditation Fountain
28. Meditation Fountain: go through the door to Magma Pool → Magma Pool
29. Magma Pool: go through the door to Training Chamber Access → Training Chamber Access (Wave Door; needs Wave Beam)

More Missile Expansions

• Missile Expansion (Burn Dome)
• Missile Expansion (Crossway)
• Missile Expansion (Dynamo)
• Missile Expansion (Dynamo)
• Missile Expansion (Furnace)
• Missile Expansion (Gathering Hall)
• Missile Expansion (Hive Totem)
• Missile Expansion (Main Plaza)
• Missile Expansion (Main Plaza)
• Missile Expansion (Main Plaza)
• Missile Expansion (Ruined Fountain)
• Missile Expansion (Ruined Gallery)
• Missile Expansion (Ruined Gallery)
• Missile Expansion (Ruined Nursery)
• Missile Expansion (Ruined Shrine)
• Missile Expansion (Ruined Shrine)
• Missile Expansion (Vault)
• Missile Expansion (Watery Hall)
• Missile Expansion (Watery Hall Access)
• Missile Expansion (Fiery Shores)
• Missile Expansion (Storage Cavern)
• Missile Expansion (Triclops Pit)
• Missile Expansion (Elite Control Access)
• Missile Expansion (Elite Research)
• Missile Expansion (Fungal Hall Access)
• Missile Expansion (Fungal Hall B)
• Missile Expansion (Main Quarry)
• Missile Expansion (Metroid Quarantine A)
• Missile Expansion (Metroid Quarantine B)
• Missile Expansion (Phazon Processing Center)
• Missile Expansion (Security Access A)
• Missile Expansion (Frost Cave)
• Missile Expansion (Gravity Chamber)
• Missile Expansion (Ice Ruins East)
• Missile Expansion (Ice Ruins East)
• Missile Expansion (Phendrana Shorelines)
• Missile Expansion (Phendrana Shorelines)
• Missile Expansion (Quarantine Monitor)
• Missile Expansion (Research Lab Aether)
• Missile Expansion (Research Lab Hydra)